The IPV4 We Didn’t Get

March 16, 2026 by 4 Comments

If you have ever read science fiction, you’ve probably seen “alternate history” stories. You know, where Europeans didn’t discover the New World until the 19th century, or the ancient Egyptians stumbled upon electricity. Maybe those things happened in an alternate universe. [BillPG] has an alternate history tale for us that imagines IPv6 was shot down and a protocol called IPv4x became prominent instead.

The key idea is that in 1993, the IP-Next-Generation working group could have decided that any solution that would break the existing network wouldn’t work. There is precedent. Stereo records play on mono players and vice versa. Color TV signals play on black and white sets just as well as black and white signals play on color TVs. It would have made perfect sense.

How could this be? The idea was to make everyone who “owns” an IPv4 address the stewards of a 96-bit sub-address block. IPv4x-aware equipment extracts the entire 128-bit address. IPv4-only equipment routes the packet to the controlling IPv4 address. Wasteful? Sure. Most people don’t need 79 octillion addresses. But if everyone has that many, then why not?

The fictional timeline has DNS and DHCP, along with dial-up stacks, changing to accommodate the new addresses. Again, you had to assume some parts of the network were still IPv4-only. DNS would return both addresses, and it was up to you to pick the IPv4x address if you understood it.

Your ISP would probably not offer you the entire extra space. A regional router could handle all traffic for your neighborhood and then direct it to your specific 128-bit address or your pool of addresses, if you have multiple devices. No need for NAT to hide your devices, nor strange router configurations to punch traffic through.

Of course, back in the real world, we have two incompatible systems: IPv4 and IPv6. IPv6 adoption has been slow and painful. We wondered why [BillPG] wrote about this future that never was. Turns out, he’s proposed a gateway that IPv6 hosts can provide to allow access from IPv4-only networks. Pretty sneaky, but we can admire it. If reading all this makes you wonder what happened to IPv5, we wondered that, too.

ATtiny85 Plays The Chrome Dinosaur Game

March 16, 2026 by No comments

If you’ve ever had your internet connection drop out while running Chrome, you’ve probably seen a little dinosaur pop up to tell you what’s going on. You might have then tapped a key and learned that it’s actually a little mini-game built into the browser where you have to hop your intrepid T-rex over a bunch of cactii. [Albert David] is well familiar with this little Easter egg, and set about building a system to automatically play the game for him.

The build uses an Digispark ATtiny85 microcontroller board to run the show. It’s set up to plug in to a PC and enumerate as a USB HID device, so it can spoof the required key presses to play the game. To sense the game state, the device uses a pair of LM393 light-dependent resistor comparator modules. The bottom sensor is used to detect cactus obstacles in the game, while the upper sensor detects flying bird obstacles. Armed with this information, the microcontroller can deliver keypresses at just the right time to jump over cactuses while dodging birds overhead.

[Albert] does a great job of explaining how the project came together in the write-up. There are also useful calibration instructions that indicate how to place the sensors and tweak their thresholds so they trigger reliably and help you net a suitably high score.

Interestingly enough, this isn’t the first time we’ve seen a microcontroller take Chrome’s hidden game for a spin. The game itself has become popular enough that we’ve also seen it ported to other platforms.
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Magnetic-Suspension Hoverboard Is Only 11 Years Late

March 15, 2026 by 14 Comments

Anyone who saw Back to the Future II was disappointed when 2015 rolled around with nary a hoverboard in sight. There have been various attempts to fake it, but none of them quite have the feel of floating about wherever you’d like to go that the movie conveys. The little-known YouTuber [Colin Furze] has a new take on the idea: use magnets. Really big magnets.

If you’re one of [Colin]’s handful of subscribers, then you probably saw his magnetic-suspension bike. We passed on that one, but we couldn’t resist the urge to cover the hoverboard version, regardless of how popular [Colin] might be on YouTube. It’s actually stupidly simple: the suspension is provided by the repulsive force between alarmingly large neodymium magnets. In this case, two are on the base plate that holds the skateboard ‘trucks’, and two are on the wooden ‘deck’ that [Colin] rides upon.

Of course magnetic repulsion is a very unstable equilibrium, so [Colin] had to reduce the degrees of freedom. In his first test, that was with a pair of rods and linear bearings. That way the deck could only move in the z-axis, providing the sensation of hovering without allowing the deck to slide off its magnetic perch. Unfortunately those pins transferred too much vibration from the ground into the deck, ruining the illusion of floating on air.

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Building A Rad Bluetooth Speaker That Didn’t Really Exist

March 15, 2026 by 9 Comments

[Nick] came across an awesome Bluetooth speaker online, only, there was a problem. It didn’t really exist—it was just a render of a device that would be nice to have. Of course, there was an obvious solution—[Nick] just had to build the device for real!

The key to the aesthetic of the build is the external case. [Nick] was able to recreate the rough design of the rendered device in SolidWorks, before having the components produced on a resin 3D printer which provided excellent surface finish. Internally, the Bluetooth audio receiver was cribbed from an old pair of wireless headphones. However, a little more oomph was needed to make the speaker really usable, so [Nick] hooked the audio output up to a small MAX98306 amplifier board and a pair of 3 W speakers. The tiny tactile buttons from the headphone PCB wouldn’t do, either. For a nicer feel, [Nick] hacked in a set of four hall effect keyboard switches to control the basic functions.

The result is a Bluetooth speaker that looks as rad as the rendered unit, only you can actually take it outside and bump some tunes! It recalls us of some fine up-cycling work we’ve seen done to vintage 80s radios in a similar vibe.

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Hackaday Links: March 15, 2026

March 15, 2026 by 2 Comments

Some days, it feels like we’re getting all the bad parts of cyberpunk and none of the cool stuff. Megacorps and cyber warfare? Check. Flying cars and holograms? Not quite yet. This week, things took a further turn for the dystopian with the news that a woman was hospitalized after an altercation with a humanoid robot in Macau. Police arrived on scene, took the bot into custody, and later told the media they believed this was the first time Chinese authorities had been called to intervene between a robot and a human.

The woman, reportedly in her seventies, was apparently shocked when she realized the robot was standing behind her. After the dust settled, the police determined it was being operated remotely as part of a promotion for a local business. We’ve heard there’s no such thing as bad publicity, but we’re not sure the maxim holds true when you manage to put an old lady into the hospital with your ad campaign.

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New Aluminum-Based Catalyst Could De-Throne Platinum Group

March 15, 2026 by 12 Comments

Platinum-group metals (PGMs) are great catalysts, but they’re also great investments — in the sense that they are very, very expensive. Just ask the guy nicking car exhausts in the Walmart parking lot. If one could replace PGMs with a more common element, like, say the aluminum that makes up over 8% the mass of this planet, it would be a boon to the chemical industry, and a bane to meth addicts. Researchers at King’s College, London have found a way to do just that, with a novel form of aluminum called cyclotrialumane.

The aluminum trimer is exactly what the ‘tri’ in the name makes it sound like: three aluminum atoms, bonded in a triangular structure that is just pointy and stick-outy enough to poke into other molecules and make chemistry happen. OK, not really — you can see from the diagram above it’s not nearly that simple — but the point is that the shape makes it a good catalyst. The trimer structure is useful in large part because it is very stable, allowing reactions to be catalyzed in a large variety of solutions.

The researchers specifically call out their trialuminum compound as effective at splitting H2 in to H+ ions, as well as ethene polymerization. Both of those are important industrial reactions, but that’s only a start for this trialuminum wonder catalyst, because the researchers claim it can catalyze totally new reactions and create previously-unknown chemicals.

If you never took chemistry, or it’s been too many years since you last slept through that class, we have a primer on catalysts here. By accelerating chemical reactions, catalysts have enabled some neat hacks, like anything involving platinum-cure silicone.

Thanks to [Lightislight] for the tip! Hacks do appear here on their own, but you can always use our tips line to catalyze the synthesis of a particular article.

Header image adapted from: Squire, I., de Vere-Tucker, M., Tritto, M. et al. A neutral cyclic aluminium (I) trimer. Nat Commun 17, 1732 (2026). https://doi.org/10.1038/s41467-026-68432-1

An animation shows an open document in LibreOffice Write. In the document are some hexadecimal opcodes. The operator selects these opcodes and changes their font to Z80 Sans, at which point they are displayed as assembly mnemonic codes.

Disassembling Opcodes With A Font

March 15, 2026 by 4 Comments

Those who stay into the forbidden realm of font rendering quickly learn how convoluted and arcane it can be – LaTeX is a fully Turing-complete programming language, Unicode has over eighty invisible characters, and there are libraries that let you execute WebAssembly in a font. A great example of a font’s hidden capabilities is Z80 Sans, a font that disassembles Z80 opcodes to assembly mnemonics.

If one pastes Z80 opcodes into a word processor and changes their font to Z80 Sans, the codes are rendered as their assembly mnemonics. The font manages this by abusing the Glyph Substitution Table and Glyph Positioning Table, two components of the OpenType standard. Fonts define relations between characters (internal representations used by the computer, such as ASCII and Unicode) and glyphs (the graphics actually displayed).

In some cases, though, the way a character is displayed depends on where it appears in a word, or what appears around it (Arabic characters are a common example, but an example from English is the ligature “æ”). Z80 Sans defines all the possible glyphs for each nibble of the opcodes, then used a recursive descent parser to generate substitution rules which display the correct glyphs in context.

For a deeper dive into the pitfalls of text graphics, check out this font rendering engine written for a hobby OS. You can also use fonts to play games or talk to an LLM.